Machine for mixing tar macadam.



E. W. BRACKENBURY;

MAUHINE PoR MIXING-TAR MAOADA'M. APPLICATION FILED TUNES, 1910.

Patented Noms, 1911.

.d UNITED STA-.TES PATENT oFFIcE.

EDWARD W. BRACKENBURY, OF MILWAUKEE, WISCONSIN, ASSIGNOR T THE T. Ia.

SMITH C0., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

l MACHINE FOR MIXING TAR MACADAM.

To all whom 'it may concert/t:

Be it known that I, EDWARD W. BRACKEN- BURY, a subject of the King of England, residing at 'Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented a'new land useful Improvement in Machines for Mixing Tar Macadam, of which the following is a specification.

My invention relates to machines to be used in street paving, and in that kind of paving in which a concrete base is laid first and is subsequently covered by a tar macadam, or bithulithic surface ;y and the objects of my invention are, first, to provide portable means for expeditiously drying and heating the stone for the mixture; second, to provide means for efficiently mixing the tar or bituminous ingredient with the stone while keeping the mixture hot, and to provide adequate means for feeding and discharging the machine. I attain these objects by the mechanism illustrated in the accompanying drawing, which 4forms a part of this specification, and in which- Figure 1 is a side view of the complete machine, and Fig. 2 is an end view of same. In the drawing I have shown a standard batch concrete mixer of the tilting type, mounted on a truck and furnished with a steam engine and boiler for motive power.

10 is the mixer drum of a well known form, which is rotated to mix and tilted to discharge as usual. .l

Numeral 31 designates the mixing blades which are secured to the drum on its interior.

11 is the feed spout through which material is introduced to the drum. Any loading device actuated by power may be substituted for this' feed spout, which is shown only as a conventional representationof a feeding means.

12 is the boiler, provided with the smoke stack 13. Connected -with this smoke stack is a laterally projecting conduit 14, which is continued in a portion 15 extending longitudinally of the truck frame. This portion 15 is supported on curved stanchions' 16. The end of the conduit 15 is loosely connected to the part 17, so that the latter may swing on 15 as a center. vThe lowerl end of the pipe 17 is provided with a plate 18, which abuts the discharge end of the drum 10. The end of the pipe 17 is also provided with a horizontally extending bar 19 clamped to the pipe, the ends of this bar be- Specification of Letters Patent.

Application led .Tune 8, 1910. Serial No. 565,685.

Patented Nov. 2s, 1911.

I ing pivotally connected to arms 20 which V are pivotally connected to a tilting part of the mixerl frame as at '21. A turn buckle 22 is provided in each arm 20, whereby the 'length of the arm may be nicely adjusted.

23 are bolts or other similar means connecting 17 and y15, but placed in circumferential slotsin one part or the, other to allow the swinging movement of 17.

It isr obvious that as the mixer 'drum 10 is tilted to discharge, the pivotal connection 21 will swing in an are around the trunnions 24, and the arms 20 will swin the pipe 17 and plate 18 entirely clear o the discharge 4end of the mixerA drum. Also whenever the .drum 10 is in itshorizontal position thepipe 17 will be in direct communication with the interior of the drum.

25 and'26 are dampers or valves in the smoke stack 13 and lateral conduit 14 re.- spectively. By means of these dempers or valves the products of combustion from the boiler Iirebox may be directed up the smoke to the mixer drum l0 whence they will pass of through the feed spoutll.

In the practical operation of mixing tar macadam the/stone and screenings for one batch is fed to the drum, valve 26 is opened and valve 25 is partly or wholly closed as the necessities of the case may require. The products of Vcombustion will fill the drum maintaining a temperature of about 600 degrees F. therein. As the drum revolves the contained stone and screenings will be lifted by the mixing blades of the drum and .will be almost continually falling through the hot gases of combustion. The contained materials vwill thus be rapidly heated, much more rapidly than while lying still in an oven. As soon'as the stone is hot and dry the tar or other bituminous substance is in troduced through the feed spout 11 and will be thoroughly mixed with the hot stone and screenings by the continuous rotation of the drum. The mixture is discharged by tilting the drum as usual, the pipe 17 swinging outward away from the discharge opening of the drum as the latter starts its tilt-l vstack or through the conduits 14, l5 and 17 stack materially aids from the engine shaft.

What I claim as my invention and desire to secure by Letters Patent is:

1. In a machine for mixing tar macadam a rotatably mounted mixing drum, means for for swinging a feedingv material to said drum through one end thereof, means for tilting said drum to discharge through its other end, a pipe .in

communication with said drum through the discharge end thereof when the drum is in mixing position-and also in communication with a source of heated gases, means for rotating said drum continuously and means part of said pipeas the drum is tilted to affordl a free discharge of the' material.

2. In a machine for mixing tar macadam, a rotatably mounted mixing drum,V means for feeding said drum through one end thereof and discharging it through the other end thereof, a steam engine and boiler affording means for rotating said drum, a pipe adapted to convey the products 0f combustion of' the boiler fire to the interior ofthe mixing drum through the discharge end thereof, a joint in said pipe allowing part of the pipe to swing relatively to the other part, means for swinging said pipe clear of the drum, and means for forcing the fire and directing the heated gases to the mixing drum or to the atmosphere.

3. A mixing machine comprising a mixing drum rotatably mounted in a tiltable frame, an attachment end of the drum when it is in mixing position, said attachment being swingingly'supported from the machine frame, and rods' pivotally attached to said swinging attachment and also to the tiltable frame at a point considerably above the center on which said frame swings,l whereby as the drum is tilted the attachment` is swung outward from the drum end, and while the mixer is in mixing position the attachment is held in posit-ion against the end of the drum.

4. In a machine lfor mixing tar macadam a rotatable mixing drum, means for feeding material to one end of said drum and for discharging it through the other end thereof, a pipe adapted to convey heated gases attached to a source of such gases at one of its ends, the other end of said pipe adapted to be held against, and to communicate with the drum through the discharge end thereof, and means for automatically moving said pipe away from said drum by the discharge operating mechanism. l

EDWARD W. BRACKENBURY.

Witnesses:

LLOYD H. DRAEG'ER, E. lV. MEYER.

fitting against the discharge 

